A stunning Manhattan federal appeals court ruling yesterday overturned the death sentence for a vicious cop-killer and gave him a second chance to plead with jurors to spare his life.

The split decision sparked outrage from NYPD officials and the widows of hero detectives Rodney Andrews and James Nemorin, who were shot execution-style by Ronell Wilson during a 2003 undercover gun buy-and-bust operation on Staten Island.

So cold-blooded was Wilson that he brazenly stuck out his tongue to taunt the family members of his victims during his sentencing.

Detectives’ Endowment Association President Michael Palladino blasted the federal judges he said “ruled in favor of a ruthless, remorseless killer” and against the clear wishes of the jury.

“When [jurors] rendered the first decision, they were emphatic, they were decisive, and there was absolutely no reservations in their hearts or in their minds by imposing the penalty of death,” Palladino said.

Holding back tears, Andrews paused, then said: “I can’t. This is too much for me.”

She then broke down crying and left the room.

Nemorin’s widow, Rose, tearfully told The Post that the ruling left her shattered.

“I’m shaking — I can’t believe it. I’m confused,” she said before breaking down behind the door of her Long Island home.

“It’s like losing it again and again and again . . . I’m just kind of in shock.”

In its 2-to-1 ruling, the Second Circuit Court of Appeals ordered a “penalty phase” retrial on grounds that prosecutors violated Wilson’s constitutional rights by citing his refusal to testify under oath when he told jurors he was “truly sorry” for the pain he caused.

“These arguments were potent — no juror found that Wilson accepted responsibility or showed remorse, and every juror found that Wilson presented a risk of future dangerousness,” Chief Judge Dennis Jacobs wrote for the majority.

In a dissenting opinion, Judge Debra Ann Livingston said it was “entirely proper” for the prosecution to question the credibility of Wilson’s unsworn statement “because it came only when Wilson faced punishment for his crime.”

A spokesman said Brooklyn US Attorney Loretta Lynch “will carefully review this decision and consider options.”

A new jury would be impaneled if Lynch opts to seek the death penalty again.